Introduction to Trim Convert and Exploring Alternatives

Trim Convert: An Introduction.

The Trim Convert option in Autodesk Alias trims the selected four-sided boundary and converts it into a new surface with natural boundaries. Trim convert or the ‘trmcvt’ option can be found under the ‘Surface edit’ window.

Trim Convert: How to use it.

Trim convert is selected by going to the ‘Surface edit’ and choosing the ‘Trim’ option.

1. This option can be performed on an enclosed four-sided surface defined by curves-on-surface.
2. The regions to be modified once selected, a crosshair appears on the selected surface to keep.
3. The ‘Convert’ option is highlighted along with the ‘Divide’ option once the region is selected at the bottom right of the workspace.
4. Once the ‘Convert’ option is selected, the selected surface is trimmed and the trimmed surface is converted into a new surface having natural boundaries.

NOTE – If the selected surface does not have four-sided boundaries, the system throws an error and the user is asked to redefine the surface.

1. If the result is unsatisfactory, there is a ‘Revert’ option available at the bottom right corner of the workspace to get back to the untrimmed surface.

Why Trim Convert?

Trim convert is mainly used as it provides the user the flexibility to work on the trimmed surface which has a natural boundary. There are several limitations to using some commands working with a trimmed surface. For example, Align. These can be overcome by using trim convert to achieve the desired continuity and smooth surfaces.  

Nuances to Trim Convert and Divide.

The divide option can be found in the ‘Trim’ option in the ‘Surface edit’ section in the Palette. The ‘Divide’ option can be found at the bottom right of the workspace once the desired surface to be manipulated is selected.

The divide option trims the selected area from the original and creates a new trimmed surface of the separated area. The following exercise will help us understand in detail the above-mentioned.

1) A torus is taken as the surface to be manipulated. This tool can be found under the surface section in the palette. Any desired shape can be considered.

2) Two curves are projected onto the surface to take a section of the torus to perform the operations.

3. The Trim Convert option is selected from under the ‘Surface edit’ section in the ‘Trim’ option as shown in Figure 3.

4.  The ‘Convert’ option can be found at the bottom right of the workspace once the desired area is selected.

5. This option creates a duplicate of the selected surface over the parent surface having natural boundaries.

6. This becomes more apparent once the surface is moved away from the original surface and now can be worked on as a new surface.

 7. Now let us take a look at the ‘Divide’ option that can be found in the ‘Trim’ option under the ‘Surface edit’ section in our palette. To perform this option, we select the desired surface similar to the trim convert operation, however, we will now choose the ‘Divide’ option.

8. Divide option, as previously mentioned, will trim the selected area to create a new trimmed surface.

9. By turning on the ‘mulcol’ option in diagnostic shading, we will notice that we have a trimmed surface that is divided from the parent surface.

10.  It is to be noted that when the CV/Hull is turned on for the divided surface, we will be able to see the divided surface as a part of the whole.

By understanding the nuances between these two seemingly similar commands, we will be able to use them accordingly when the situation presents itself during class-A surface modeling.